Crystalline copolymers



3,513,140 CRYSTALLINE COPOLYMERS James Keith Hambling, Frimley, nearAldershot, Hampshire, Great Britain, and David Allinson Woodhead,Shepperton, Middlesex, Northern Ireland, assignors to The BritishPetroleum Company Limited, London, England, a corporation of England NoDrawing. Filed Nov. 22, 1967, Ser. No. 684,933 Claims priority,application Great Britain, Nov. 29, 1966, 53,404/ 66 Int. Cl. C08f 15/40US. Cl. 26080.78 3 Claims ABSTRACT OF THE DISCLOSURE Transparentcrystalline polymers of improved tensile strength and malleabilitycontain units derived from a branched chain monoolefin of 46 carbonatoms and at least some but less than 5% of units derived from at leastone branched chain alpha octene. The polymers may be prepared bypolymerising the branched C monoolefin with the branched chain alphaoctene in the presence of a catalyst obtained from (a) a solidcrystalline compound of a metal selected from Groups IV, V, VI, VII orVIII, the metal being in a lower valency state than its maximum and (b)an organometallic compound of a metal selected from Groups I, II or III.

This invention relates to a process for the production of crystallinecopolymers and to the copolymers themselves.

According to the present invention there is provided a process for theproduction of a crystalline copolymer which process comprisespolymerising a branched chain alpha mono-olefin containing 4-6 carbonatoms per molecule with at least one branched chain alpha octene in thepresence of a catalyst obtained from (a) a solid crystalline compound ofa metal selected from Groups IV, V, VI, VII or VIII of the PeriodicTable according to Mendeleef, the metal being in a lower valency statethan its maximum and (b) an organo-metallic compound of a metal selectedfrom Groups I, II or III of the table.

Preferably the feedstock contains from 50 to 90% by volume of the Colefin and from 10 to 50% by volume branched chain octenes.

A very suitable C olefin is 4-methylpentene-l.

A very suitable source of branched chain octenes is that fractionobtained as a distillation cut between 110 C. and 111.5 C. from the baseproducts of a butene-ethylene codimerisation process. A suitableethylene-butene codimerisation process is described in our British Pat.No. 962,255.

Preferably the crystalline compound is a halide of a transition element.Most preferably it is titanium trichloride.

Preferably the organo-metallic compound is a compound of aluminium andmost preferably an alkyl alumminium halide. The preferred alkylaluminium halide is aluminium diethyl monochloride.

Preferably the molar ratio of component (a) of the catalyst to component(b) is in the range 1:1 to 1:10., most preferably in the range 1:1 to1:4.

Polymerisation may be elfected in the presence of an inert diluent whichis a non-solvent for component (a) of the catalyst. Suitable diluentsinclude normally liquid hydrocarbons, for example, heptane, octane,benzene, toluene and xylene.

Polymerisation may be carried out in the absence of solvents for themonomers whilst maintaining the monomers in the liquid state if desired.

Preferably polymerisation is carried out at a tempera- Unitcd StatesPatent 0 3,513,140 Patented May 19, 1970 ice ture in the range -20 to+120 0., most preferably in the range 20 to C.

Preferably the concentration of component (a) of the catalyst liesbetween 0.1 and 50, most preferably between 0.5 and 30 millimoles perlitre of reaction medium.

The pressure may be sub-atmospheric, atmospheric or super-atmospheric.

By reason of the different reactivities of the C olefins and the Colefins, only minor amounts, less than 5% by weight, of octenes can beincorporated into the copolymers.

Nevertheless, the presence of the octenes has been found to have abeneficial effect on the course of the copolymerisation reaction and thepresence of units derived from the octenes has been found to producecopolymers having physical propertie superior in many ways tohomopolymers qt 4-methylpentene-1.

The octenes control the molecular weight of the copolymers to aconsiderable extent and, indeed, result in the production of copolymerswhose molecular weights are sufficiently low to permit them to beprocessed by injection moulding without degradation.

If, however, the preparation of an easily extrudable copolymer isdesired, then it is necessary to effect copolymerisation in the presenceof an additional molecular weight control agent, e.g., hydrogen.

In general, Ziegler-type polymerisations are carried out in the presenceof an inert diluent. If, however, the quantity of diluent is reduced oreliminated then the rate of reaction is increased.

The presence of the octenes reduces the rate of the reaction in thepresent process. This may not be a desired effect. However, by operatingwith reduced quantities or in the absence of a diluent, the ratereducing effect of the octenes is counter-balanced by the rateincreasing efiect of reduced diluent concentration and normal reactionrates can be achieved.

Insofar as the polymers themselves are concerned, the presence of unitsderived from the octenes confers a marked increase in tensile strengthand malleability, especially at elevated temperature, when compared withhomopolymers of 4-methylpentene-l.

The copolymers are clear, transparent, colourless materials. Thusaccording to another aspect of the present invention there is provided acrystalline copolymer containing units derived from a branched chainalpha monoolefin containing 4-6 carbon atoms per molecule and at leastsome but less than 5% of units derived from at least one branched chainalpha octene.

The invention is illustrated by the following example.

EXAMPLE A copolymer of 4-methylpentene-1 and a mixture of branched chainalpha octenes was prepared as follows:

A 5 l. S-neck glass reactor was fitted with a paddle stirrer,thermometer pocket, cold finger and suitable catalyst/monomer entrytubes.

The reactor was placed in an oil bath, urged with dry nitrogen andcharged with 1600 ml. 4MP1 and 400 ml. of a branched octene distillationcut C.-11l.5 C.) ex butee-ethylene codimerisation process.

3.5 g. of titanium trichloride and 6.5 g. aluminium diethyl monochloridewere washed in with ml. dry n-heptane. The oil bath temperature wasincreased to 50 C. over a period of 30 mins., and reaction temperaturecontrolled at 50 C. by use of the cold finger. A slow bleed of nitrogen(ca. 5 litres per hour) was maintained through the reactor to ensurecomplete absence of oxygen.

After 6 hours the catalyst was deactivated with 500 ml. methanolcontaining 50 ml. acetyl acetone and the polymer precipitated by pouringthe resultant slurry into 3 litres of methanol.

Monomer analysis later revealed that the reaction had virtually ceasedafter 5 hours After washing with methanol and acetone at roomtemperature and drying under vacuum at 70 C., 575 g. copolymer, wasrecovered.

No external molecular weight control agent was used yet the copolymerwas processed without difiiculty.

By way of comparison a homopolymer of 4-rnethylpentene-l was prepared ina similar fashion, but in the presence of external molecular weightcontrol (necessary to permit processing).

The properties of the copolymer and the homopolymer are set out in thefollowing table.

Homopolymer, Property Copolymer 4MP1 Tensile strength, p.s.i.:

130 c 1, 200 700 Elongation at yield, percen 100 0 12 Vicat softeningpoint, C 130-150 180 Impact strength, 0., ft. 1bs./in.:

Izod notched. 0. 9 1. 2

2. 9x10 2. 0x10 0. 5x10 0. 7x10 0 10 0 10 0 20x10 0. 25x10 What we claimis:

1. Transparent crystalline copolymer products containing units of abranched chain alpha mono-olefin containing 4-6 carbon atoms permolecule and units of a branched chain alpha octene, up to 5% of theunits by weight of said products being branched chain alpha octeneunits.

2. Crystalline copolymer products according to claim 1 wherein the C Colefin is 4-methylpentene-l.

3. Crystalline copolymer products according to claim 2 wherein thebranched chain alpha octene units are units of a fraction of codimerizedbutene-ethylene distilling between C. and 111.5 C.

References Cited UNITED STATES PATENTS 3,029,215 4/1962 Campbell2'6033.6

JOSEPH L. SCHOF ER, Primary Examiner R. S. BENJAMIN, Assistant ExaminerUS. Cl. X.R. 26()-88.2

52%;? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION mm No.3,513,140 mad May 19, 1970 Inventofls) James Keith Rambling and DavidAllinaon Woodhead It is certified that error nppearl 1n theabove-identified patent and that said Letterl Patent are herebycorrected as shown below:

In the heading of the printed specification,

Column 1, line 5, "Northern Ireland" should read:

-- England SIGNED AND SEALED stream L .J Edmdliletcbeglr. my m: 1: a 0mmflomissiom or Paws

